You can hear the sound of former bustling coral reefs dying due to the impact of human activity, according to new research.

Believe it or not, coral reefs are among the noisiest environments on our planet and healthy reefs can be heard using underwater microphones from kilometres away.

However, scientists have found that coral reefs affected by human activity, such as overfishing, are much quieter than protected reefs, which can have a big impact on the fish and invertebrates, which rely on them for survival.

Led by Dr Julius Piercy, from the University of Essex, the study involved taking acoustic recordings of coral reefs with different levels of protection around islands in the Philippines. The research found that the noise produced by the few remaining resident fish and crustaceans on unprotected reefs was only one third of the sound produced at bustling, healthy reef communities.

This is particularly important to the larval stages of reef fish and invertebrates, which spend the first few days of their life away from reefs and use sound as an orientation cue to find their way back. With less sound being produced, the distance over which larvae can detect habitat is ten times less, impacting on the replenishment of future generations needed to build up and maintain healthy population levels.